Best overall
Honda EU2200i
2,200W start · 1,800W run
Gasoline · Inverter · 48–57 dBA · 47 lb
The benchmark quiet inverter — legendary engine reliability and clean power (<3% THD) for sensitive electronics.
Find on AmazonWhat size generator to run a electric space heater?
Short answer
A electric space heater draws about 1,500 watts and has no motor surge, so a generator rated for at least 1,500 watts can run one on its own — a 2,000W unit gives comfortable headroom for anything else you add.
Running watts
1,500W
Starting watts
1,500W
Minimum generator
1,500W
Recommended
2,000W
Sizing a generator for a electric space heater
A electric space heater is a resistive load with no motor, so its starting and running watts are the same — about 1,500 watts. You only need to cover that steady draw, plus headroom for anything else on the generator.
To run one on its own, choose a generator rated for at least 1,500 starting watts. To run it alongside other essentials, add up everything you need and size up — the calculator below does that math for your exact list.
Run your full appliance list
This page covers the electric space heater on its own. Open the calculator with it pre-selected, then add everything else you plan to power at the same time.
Size a generator with a electric space heaterRecommended recreational / portable generators
Real, widely available units in the Up to 3,500W class. Independent picks — we're not affiliated with any manufacturer or retailer and earn nothing from these links.
Best value
Westinghouse iGen2200
2,200W start · 1,800W run
Gasoline · Inverter · 52 dBA · excellent fuel economy
Matches the Honda’s 1,800W running output for a fraction of the price, and sips even less fuel.
Find on AmazonBudget pick
Champion 2500W Dual Fuel Inverter (201183)
2,500W start · 1,850W run
Dual fuel (gas / propane) · Inverter · CO Shield auto-shutoff · ultralight
Runs on gasoline or propane and includes a built-in carbon monoxide shutoff sensor.
Find on AmazonFrequently asked questions
What size generator do I need to run a electric space heater?
To run a electric space heater on its own you need a generator rated for at least 1,500 starting watts. We recommend a 2,000W (recreational / portable) unit so you have headroom to add other appliances without running the generator at its limit.
How many watts does a electric space heater use?
A electric space heater uses about 1,500 watts. It has no motor, so its starting and running watts are the same. Always check your unit's nameplate for exact figures.